Construction workers are often called upon to transport construction materials and equipment onto the roof portion of a building. The materials may include roofing shingles, plywood sheets, bricks, ventilation units or even ornamental structures. Various lifting devices have been employed to accomplish this task. Such devices often require multiple persons to operate, have limited safety features and are often quite expensive to purchase and maintain.
Applicant proposes a load lifting system used in conjunction with a ladder, and a method to move a load to the roof of a building. The system is comprised of a carriage that rolls along the rails of conventional extension ladders and a self-contained hoisting mechanism for raising a load to the roof surface of a building.
The carriage of Applicant's lifting system includes a dual braking mechanism that reduces the risk of a loaded carriage sliding or rolling down the ladder during a lift or off of the roof once the load is brought to the roof surface. Applicant's lifting system also includes ladder rail adaptors to provide for a smooth transition of the carriage as it rolls along the rails of extension ladders and an eave adaptor to provide for a smooth roll surface between the ladder rails and the roof surface. The proposed lifting system also includes an infinitely adjustable ladder support to provide an intermediate support to the extension ladder.